Aaron Turner Equipment What is an example of a guitar that Aaron Turner used? used two different guitars: a 1976 Fender Telecaster Custom (black), and a 1975 Fender Telecaster Deluxe (brown),
What type of amplifiers did he use?
What type of amplifiers did Aaron Turner use?
Touring with Isis in 2007, Turner used two different guitars: a 1976 Fender Telecaster Custom (black), and a 1975 Fender Telecaster Deluxe (brown), played through various effects (his pedalboard layout changed every gig depending on what songs the band decided to play that night), a VHT/Fryette Pitbull Ultra Lead, and two 4x12 Sunn cabinets. He has also acquired a custom guitar from the Electrical Guitar Company (as did fellow Isis guitarist Michael Gallagher).  In the past, Turner has also used a Gibson Les Paul Standard, PRS CE24, and has played through Sunn, Mesa Boogie, and Mackie amplifiers.  When playing with Isis, Turner and his fellow guitarists usually tuned their instruments (low to high) B-F#-B-E-G#-B, to achieve a heavier sound. They also used other tunings, though less frequently, such as F# (octave below)-F#-B-E-G#-B.  In 2016, Turner described the live rig he used with SUMAC as consisting of two custom-built guitars from the Electrical Guitar Company. Both have lucite bodies and aluminum necks, and custom-wound wide frequency range pickups. The newer of the two--a prototype for a signature model--has a slightly flatter fingerboard radius than the older instrument. On a tour of the Eastern US, Turner was using an Orange Dual Dark 100 amplifier head with a slaved Fryette Two/Ninety/Two power amp. Both heads drove Orange and Marshall cabinets, though Turner claimed to have no strong preferences for particular speaker cabinets. While recording, Turner prefers to use a Fryette Pitbull Ultra Lead, an amp model he's used consistently since his work in Isis. Turner described using a variety of effects pedals in his live rig. Specifically, he runs a BOSS TU-3 Chromatic Tuner, a Death By Audio Apocalypse fuzz, a MASF fuzz, a Strymon BlueSky reverb (which he described as the one essential pedal in his rig), a TC Electronics Ditto Looper X2, and an EHX Forty-Five Thousand sampler (used to trigger preset samples during performance. Turner prefers a Heil PR20 vocal microphone. CANNOTANSWER
In the past, Turner has also used a Gibson Les Paul Standard, PRS CE24, and has played through Sunn, Mesa Boogie, and Mackie amplifiers.
Aaron Turner (born November 5, 1977) is an American musician, singer, graphic artist, and founder of label Hydra Head Records. He is most widely known for his role as guitarist and vocalist for the post-metal bands SUMAC and Isis, while also participating in several other bands and projects such as Old Man Gloom, Lotus Eaters and Split Cranium, a collaboration with Jussi Lehtisalo of Finnish band Circle who toured with Isis in 2009.

Though raised in New Mexico, Turner moved to the Boston area where he attended school and formed Isis and Hydra Head. In June 2003, Turner moved operations of both the band and label to Los Angeles, California. Turner now resides in Vashon, WA which is also the base of operations for Hydra Head and his various other activities.

In partnership with his wife Faith Coloccia, Turner founded another record label, SIGE, in March 2011. It has gone on to release material from his musical collaboration with Coloccia, Mamiffer. SIGE is distributed by The Business.

Personal life 

Turner was born in Springfield, Massachusetts on November 5, 1977. At an early age, his family moved to New Mexico, where he was raised. His mother was a teacher "who taught a progressive curriculum" and his father an author, "mainly [of] non-fiction". Turner describes his upbringing, surrounded by his parents' writer, artist and photographer friends, as "creatively nurturing". At age 17, he started a company that sold rare punk rock records via mail-order. He later moved to Boston to attend art school at the School of the Museum of Fine Arts, and in 1995 began releasing music. By 1997, the Hydra Head label was becoming a respectable small record label. Turner describes his early industriousness as being motivated in part by boredom:

I grew up in New Mexico, and there wasn't a whole lot as far as youth culture is concerned. Especially when I started to get interested in straight edge and wasn't doing drugs anymore, there was really nothing for me to do. So that was like a big reason for me, I suppose, to become really productive. Also, I've never been a really social person. So there's not a lot of time taken up by my social life. And music has always been a very very big part of my life. I guess just a combination of those factors is why everything got started so early.

Around 1997–99, Turner was living with future Isis bassist and co-founder Jeff Caxide; until this point, he had been a member of the bands Union Suit and Hollomen. Isis was formed in 1997 out of a dissatisfaction with said bands' musical direction and Turner and Caxide's respective degrees of creative control.

In mid-2009, Turner moved from Los Angeles, where both Isis and Hydra Head Records were based at the time, to Seattle with his then-girlfriend, Faith Coloccia; they went on to wed in September of the same year.

Equipment 

Touring with Isis in 2007, Turner used two different guitars: a 1976 Fender Telecaster Custom (black), and a 1975 Fender Telecaster Deluxe (brown), played through various effects (his pedalboard layout changed every gig depending on what songs the band decided to play that night), a VHT/Fryette Pitbull Ultra Lead, and two 4x12 Sunn cabinets. He has also acquired a custom guitar from the Electrical Guitar Company (as did fellow Isis guitarist Michael Gallagher).

In the past, Turner has also used a Gibson Les Paul Standard, PRS CE24, and has played through Sunn, Mesa Boogie, and Mackie amplifiers.

When playing with Isis, Turner and his fellow guitarists usually tuned their instruments (low to high) B-F#-B-E-G#-B, to achieve a heavier sound. They also used other tunings, though less frequently, such as F# (octave below)-F#-B-E-G#-B.

In 2016, Turner described the live rig he used with SUMAC as consisting of two custom-built guitars from the Electrical Guitar Company.  Both have lucite bodies and aluminum necks, and custom-wound wide frequency range pickups.  The newer of the two—a prototype for a signature model—has a slightly flatter fingerboard radius than the older instrument. On a tour of the Eastern US, Turner was using an Orange Dual Dark 100 amplifier head with a slaved Fryette Two/Ninety/Two power amp.  Both heads drove Orange and Marshall cabinets, though Turner claimed to have no strong preferences for particular speaker cabinets. While recording, Turner prefers to use a Fryette Pitbull Ultra Lead, an amp model he's used consistently since his work in Isis. Turner described using a variety of effects pedals in his live rig.  Specifically, he runs a BOSS TU-3 Chromatic Tuner, a Death By Audio Apocalypse fuzz, a MASF fuzz, a Strymon BlueSky reverb (which he described as the one essential pedal in his rig), a TC Electronics Ditto Looper X2, and an EHX Forty-Five Thousand sampler (used to trigger preset samples during performance.  Turner prefers a Heil PR20 vocal microphone.
When playing with Sumac he uses two distinct tunings being A-F#-B-D-F#-B and A#-F-A#-D-F#-A#.

Musical influences 

Turner cites Pink Floyd, King Crimson, Godflesh, Neurosis, and Led Zeppelin as influences on Isis' sound.  However, he points to the electronica, krautrock and hip hop genres as shaping the group's rhythmic focus and use of sampling, as well as their occasional digressions into ambient passages. He has also listed Melvins, Jimi Hendrix, Swans, Keiji Haino, Oxbow, Earth, and Coil as among his favorite artists, and has noted that Megadeth, Metallica, and Slayer were important to his early interests in the guitar. In addition, he has noted Black Sabbath as an influence during his formative years.

Discography

Solo 

 Interminable Conniption (2019), The Tapeworm / Sige
 Repression's Blossom (2019), Sige

With Daniel Menche 

 NOX (2017), Sige

With Doolhof 

 Doolhof (2020), Sige

With Drawing Voices 

 Drawing Voices (2007), Hydra Head Records

With Greymachine 

 "Vultures Descend" (2009), Hydra Head Records
 Disconnected (2009), Hydra Head Records

With Hollomen 

 "Brand New Genius" [single] (1997), Hydra Head Records

With House of Low Culture

 Submarine Immersion Techniques Vol. 1 (2000),   Activities
Gettin' Sentimental EP (2002), Robotic Empire
 Edward's Lament (2003), Neurot Recordings
 Live from the House of Low Temperature! EP (2004), Hydra Head Records
 Chinatown Squalls EP (2007), En/Of
 Housing Tracts Compilation (2010), Sige
 Uncrossing / Ice Mole Split EP with Mamiffer (2010), Utech Records
 Lou Lou... In Tokyo Split with Mamiffer and Merzbow (2011), Sige
 Cloey / Spoiled Fruits of the Kingdom (Demo) Split EP with Mamiffer (2011), Sige
 Perverted Scripture / Silent Night Split EP with Mamiffer (2011), Sige
 Poisoned Soil (2011), Taiga Records/Sub Rosa
 Mamiffer + HOLC Split EP with Mamiffer (2013), Sige
 House of Low Culture / Caustic Touch / Daniel Menche / EMS Split (2017), Accident Prone
 Irretrievable (2020), Sige

With Isis

 Mosquito Control (1998), Escape Artist Records
 The Red Sea (1999), Second Nature Recordings
 Sawblade (1999), Tortuga Recordings
 Isis / Pig Destroyer (2000) (Split with Pig Destroyer), Relapse Records
 Celestial (2000), Escape Artist Records
 SGNL>05 (2001), Neurot Recordings
 Oceanic (2002), Ipecac Recordings
 Panopticon (2004), Ipecac Recordings
 In the Fishtank 14 (2006) collaboration with Aereogramme, Konkurrent
 In the Absence of Truth (2006), Ipecac Recordings
 Wavering Radiant (2009), Ipecac Recordings
 Melvins / Isis (2010) (Split with Melvins), Hydra Head Records

With Jodis 

 Secret House (2009), Hydra Head Records
 Black Curtain (2012), Hydra Head Records

With Jon Mueller 

 In the Falls (2021), Sige

With Lotus Eaters 

 Alienist on a Pale Horse [EP] (2001), Double H Noise Industries
 Mind Control for Infants (2002), Neurot Recordings
 Lotus Eaters [EP] (2002), Drone Records
 Wurmwulv (2007), Troubleman Unlimited Records

With Mamiffer

 Hirror Enniffer (2008), Hydra Head Records
 Uncrossing / Ice Mole Split EP with House of Low Culture (2010), Utech Records
 Iron Road II / Fake Witch Split 12" with Oakeater (2011), Sige
 Lou Lou... In Tokyo Split with House of Low Culture and Merzbow (2011), Sige
 Perverted Scripture / Silent Night Split EP with House of Low Culture (2011), Sige
 Mare Decendrii (2011), Sige
 Bless Them That Curse You Collaboration LP with Locrian (2011), Sige
 Mamiffer / Pyramids Split LP with Pyramids (2012), Hydra Head Records
 Enharmonic Intervals (for Paschen organ) Collaboration LP with Circle (2013), Sige
 Statu Nascendi (2014), Sige
 Crater Collaboration LP with Daniel Menche (2015), Sige
 The World Unseen (2016), Sige
 Recordings For Lilac III limited cassette (2017), The Tapeworm
 The Brilliant Tabernacle (2019), Sige
 Ae/Be EP, (2020), Sige
 Mettapatterning for Constellation, (2020), Sige

With Marshall Trammell
 Experimental Love I & II (2020), Sige

With Old Man Gloom

 Meditations in B (1999), Tortuga Recordings
 Seminar II: The Holy Rites of Primitivism Regressionism (2001), Tortuga Recordings
 Seminar III: Zozobra (2001), Tortuga Recordings
 Christmas Eve I and II + 6 [EP] (2003), Tortuga Recordings
 Christmas (2004), Tortuga Recordings
 No (2012), Hydra Head Records
 The Ape of God (2014), Profound Lore
 Mickey Rookey Live at London (2016), Ektro Records
 Seminar IX: Darkness of Being (2020), Profound Lore
 Seminar VIII: Light of Meaning (2020), Profound Lore
 Willing Vessel / Storms in our Eyes [EP] (2020), Sige

With Pharaoh Overlord
 6 (2020), Rocket Recordings

With Split Cranium 
 Sceptres To Rust 7-inch (2012), Self Released
 Split Cranium (2012), Hydra Head
 I'm the Devil and I'm OK (2018), Ipecac Recordings

With Sumac
 The Deal (2015), Profound Lore
 What One Becomes (2016), Thrill Jockey
 Before You I Appear EP (2016), Thrill Jockey
 American Dollar Bill – Keep Facing Sideways, You're Too Hideous to Look at Face On with Keiji Haino (2018), Thrill Jockey
 Love in Shadow (2018, Thrill Jockey)
 Even for Just the Briefest Moment Keep Charging This "Expiation" Plug in to Making It Slightly Better with Keiji Haino (2019, Trost)
 May You Be Held  (2020, Thrill Jockey)

With Summer of Seventeen
 Summer of Seventeen  (2020, Karlrecords)

With Tashi Dorji 
 Turn!Turn!Turn (2019), Sige

With Thalassa 

 Bonds of Prosperity (2017), Sige

With Twilight 

 Monument to Time End (2010), Southern Lord Records

With Unionsuit 

 Demo tape (1996), Hydra Head Records
 Accidents Happened [EP] (1997), Second Nature Recordings

As a guest contributor 

 27 – Let the Light in (2004), Hydra Head Records
 Turner contributes vocals to the track "April".
 Boris – Heavy Rocks (2011), Sargent House
 Turner contributes to the track "Aileron".
 Chelsea Wolfe – Hiss Spun (2017), Sargent House
 Guest vocals on the track "Vex"
 Converge – Converge / Napalm Death, self-released
 Guest on "Wolverine Blues" (originally performed by Entombed).
 Dekathlon – The Thin Road 7″ (2019), Ektro Records
 Guest vocals and guitar
 Full of Hell – Trumpeting Ecstasy (2017), Profound Lore Records
 Guest vocals on "Crawling Back To God"
 Lustmord – O T H E R (2008), Hydra Head Records
 Turner contributes guitar to the track "Element".
 Pelican – What We All Come to Need (2009), Southern Lord Records
 Turner contributes guest guitar to the title track.
 Puscifer – "V" Is for Viagra. The Remixes (2008), Puscifer Entertainment
 Turner provides the track "Trekka (The Great Unwashed Mix)".
 Samuel Kerridge – The I is Nothing (2018), Downwards Records
guest on "Propagates of Desire".
 Ringfinger – Decimal (2007), Little Black Cloud Records
 Turner contributes vocals and guitar to the track "Waving Good-Bye".
 Wolves in the Throne Room – Turner provides chants on "Subterranean Initiation" (2011)

Artwork 

Turner's artwork tends toward the abstract or surreal, often depicting strange or fantastic landscapes and structures.  His work on album covers, concert posters, and other music-related graphics is distinct from typical work in heavy metal or rock graphic design.  In part, this may be because of the way that Turner views his objectives in creating designs, which he has discussed on his blog in response to criticism of the clarity of text on one of his concert posters:

I also generally reject the idea that posters and album sleeves and T-shirts have to be marketing tools with overly obvious type/graphics, as opposed to more artistically oriented pieces that invoke the true spirit of the music they are intended to represent. if the bands being represented aren't writing 3 minute pop songs with inane choruses that beat the listener into submission, why should the representative graphics serve that purpose? i like to think the audience that follows these bands isn't the type of audience that requires overly simplified/commercial imagery and type in order to draw their attention to the "product". it is precisely the type of corporate design mentality as exemplified by the statement above that i have striven to avoid with what i do in the realm of music related graphics. we're not trying to sell our music to wal-mart shoppers, so if you expect our graphic personality to fall in line with what you were taught in design school about corporate branding and "truly effective" type and illustration techniques you shall be continually disappointed. clean type has its time and place, but this poster which is meant to showcase the personality of our label and by extension the show itself isn't it. music related design can be art simply beyond the idea of selling something...

In 2008, Turner's artwork was featured in a FIFTY24SF Gallery group show entitled Catalyst.
Turner has created album covers and liner note artwork for a variety of artists and bands, many of whom are signed to Hydra Head Records or Tortuga Recordings.

 27 – Let the Light In
 5ive – 5ive, Telestic Disfracture
 Aereogramme – Seclusion
 Agoraphobic Nosebleed – PCP Torpedo, Frozen Corpse Stuffed with Dope
 A Life Once Lost – The Fourth Plague: Flies
 Beecher – Breaking the Fourth Wall
 Bloodlet – Entheogen
 Burst – Prey on Life
 Cable – Northern Failures
 Cave In – Antenna, Planets of Old, White Silence
 Cavity – Laid Insignificant
 Clouds – We Are Above You
 Coalesce – There is Nothing New Under the Sun
 Converge – Petitioning the Empty Sky, When Forever Comes Crashing
 Craw – Bodies for Strontium 90
 The Dillinger Escape Plan – The Dillinger Escape Plan
 Drowningman – Drowningman Still Loves You
 The Dukes of Nothing – War & Wine
 Eugene Robinson – Fight
 Hematovore – Untitled
 The Hollomen – The Hollomen
 The Hope conspiracy – demo
 Isis – Mosquito Control, The Red Sea, Sawblade, Celestial, SGNL>05, Oceanic, Live.01, Panopticon, Live.02, Oceanic Remixes and Reinterpretations, Live.03, Live.04, Clearing the Eye, In the Absence of Truth, Shades of the Swarm, "Not in Rivers, but in Drops", Wavering Radiant, Isis / Melvins
 James Plotkin's Atomsmasher – Atomsmasher
 Jesu – Silver, Lifeline, Conqueror, Jesu, Why Are We Not Perfect?
 Jodis – Secret House
 Johnny Truant – The Repercussions of a Badly Planned Suicide
 KEN mode – Mongrel
 Kid Kilowatt – Guitar Method
 Knut – Terraformer, Wonder
 Mare – Self-Titled EP
 Milligram – Hello Motherfucker
 Mistle Thrush – Drunk with You
 Neurosis – Sovereign, Neurosis & Jarboe (remastered)
 Old Man Gloom – Meditations in B, Seminar II: The Holy Rites of Primitivism Regressionism, NO
 Panic – Dying For It
 Pelican – Australasia, The Fire in Our Throats Will Beckon the Thaw, City of Echoes
 Premonitions of War – Left in Kowloon
 Rosetta – The Galilean Satellites
 Torche – Meanderthal
 Tusk – Get Ready
 Xasthur – All Reflections Drained
 Zozobra – Harmonic Tremors, Bird of Prey''

References 
Footnotes

Citations

1977 births
Living people
Isis (band) members
American graphic designers
American heavy metal guitarists
American heavy metal singers
American experimental musicians
Shoegazing musicians
Guitarists from New Mexico
People from Santa Fe, New Mexico
American male guitarists
21st-century American singers
Old Man Gloom members
Twilight (band) members
Multi-amp guitar rigs use two or more amplifiers to create a unique tone that could not be achieved with the use of only one amplifier.  Guitar players such as James Valentine (Maroon 5) and Joh la’Mayær use multiple amplifiers simultaneously to achieve their tones.  Session guitar players such as Brent Mason often bring four or more amplifiers to recording sessions.  There are many different types of guitar amplifiers that have drastically different sounds.  There are three classic guitar amplifier circuits that most amplifiers are based on that all use different power amplifier tubes:  The EL84 powered class A circuits which comes from the Vox AC30 and AC15 amplifiers,  The 6L6 and 6V6 powered class AB circuits which come from Fender amplifiers, and the EL34 powered class AB circuits which come from Marshall amplifiers.  The sonic characteristics of these different amplifier configurations are extremely different and for a lot of guitar players it is important to have the tonal palette of all three.  This is especially true for studio guitarists and is why a lot of high-end recording studios have multiple different types of guitar amplifiers in house.  It is a common practice to use a 6L6 or 6V6 powered amplifier for a clear, clean tone in conjunction with an EL34 or EL84 powered amplifier for a more distorted tone.  It is then a matter of blending the two amps' signals in order to achieve the desired amount of distortion.

Use of Effects with Multiple Amplifiers 

The use of effects with multiple guitar amps is a common way to achieve a "bigger-sounding" tone.  One of the most common and easiest ways to achieve this is through the use of a stereo delay unit. The guitar's signal enters the delay unit and gets split into two signals.  One signal will usually be kept dry and go to one amplifier while the other signal will be delayed be a specific amount of time depending on the tempo of the song and go to the other amplifier.  This creates a much bigger sounding guitar tone than just one mono delay feeding one amplifier.  Oftentimes in the studio, dry and wet signals will be panned left and right in the mix to create a better stereo image.  This can be heard on a lot of Coldplay recordings.  Other common effects that are used with multi-amp rigs are stereo reverbs.  Stereo reverbs are often used with two of the same amp.  The advantage of using effects with multiple guitar amplifiers is that one can amplify a dry signal while another amplifies a wet signal with effects and the two signals can be blended in parallel.  A lot of guitar effects don't feature any kind of mix function so using two amplifiers allows the user to dial in the amount of effects being heard.

Common Problems using Multiple Guitar Amplifiers 

The most common problem with using multiple guitar amplifiers is that the phase of the amplifiers does not always line up.  If the two amplifiers are 180° out of phase, then the sound will be very thin sounding.  Most of the time, this can be fixed by reversing the polarity on the connection between one of the amplifiers and that amplifiers speaker.  However, there are units such as the radial phazer that can provide a more exact alignment of phase.  Another common problem with using multiple guitar amplifiers is that it can cause ground loops.  Ground loops happen when multiple amplifiers are running off of the same AC power source.  Signal gets from one amplifier to the other through the ground connection and causes a loud hum.  The most simple way around this is to simply use a three-prong to two-prong adapter on one of the amplifiers.  This lifts the ground connection and breaks the loop.  To avoid the safety hazard of lifting the ground on a high-powered amplifier, a lot of people use transformers to isolate the signals going to the amplifiers to solve the ground loop problem.  This is much more expensive but safer.

Instrument amplifiers An instrument amplifier is an electronic device that converts the often barely audible or purely electronic signal of a musical instrument into a larger electronic signal to feed to a loudspeaker. An instrument amplifier is used with musical instruments such as an electric guitar, an electric bass, electric organ, synthesizers and drum machine to convert the signal from the pickup (with guitars and other string instruments and some keyboards) or other sound source (e.g, a synthesizer's signal) into an electronic signal that has enough power, due to being routed through a power amplifier, capable of driving one or more loudspeaker that can be heard by the performers and audience. 

Combination ("combo") amplifiers include a preamplifier, a power amplifier, tone controls, and one or more speakers in a cabinet, a housing or box usually made of hardwood, plywood or particleboard (or, less commonly, moulded plastic). Instrument amplifiers for some instruments are also available without an internal speaker; these amplifiers, called heads, must plug into one or more external speaker cabinets. Instrument amplifiers also have features that let the performer modify the signal's tone, such as changing the equalization (adjusting bass and treble tone) or adding electronic effects such as intentional distortion/overdrive, reverb or chorus effect.

Instrument amplifiers are available for specific instruments, including the electric guitar, electric bass, electric/electronic keyboards, and acoustic instruments such as the mandolin and banjo. Some amplifiers are designed for specific styles of music, such as the "traditional"-style "tweed" guitar amplifiers, such as the Fender Bassman used by blues and country music musicians, and the Marshall amplifiers used by hard rock and heavy metal bands.

Unlike home "hi-fi" amplifiers or public address systems, which are designed to accurately reproduce the source sound signals with as little harmonic distortion as possible and without changing the tone or equalization (at least not unless the hi-fi owner adjusts it themselves with a graphic equalizer), instrument amplifiers are often designed to add additional tonal coloration to the original signal, emphasize (or de-emphasize) certain frequencies (most electric guitar amps roll off the very high frequencies), and, in the case of guitar amplifiers designed for electric guitar or Hammond organ, offer the capability to intentionally add some degree of "overdrive" or distortion to the tone. The two exceptions are keyboard amplifiers designed for use with digital pianos and synthesizers and "acoustic" instrument amplifiers for use with acoustic guitar or fiddle in a folk music setting, which typically aim for a relatively flat frequency response (i.e., no added colouration of the sound) and little or no distortion of the signal.

Types

Guitar amplifiers

A guitar amplifier amplifies the electrical signal of an electric guitar (or, less commonly, with acoustic amplifiers, an acoustic guitar) so that it can drive a loudspeaker at sufficient volume for the performer and audience to hear. Most guitar amplifiers can also modify the instrument's with controls that emphasize or de-emphasize certain frequencies and add electronic effects. String vibrations are sensed by a suitable microphone or pickup, depending on the type of guitar. For electric guitars, strings are almost always made of metal, and the pickup works by electro-magnetic induction (these are called magnetic pickups; they are the most widely used type of pickup on electric guitars). Acoustic guitars do not usually have a built-in pickup or microphone, at least with entry-level and beginner instruments. Some acoustic guitars have a small condenser microphone mounted inside the body, which designed to convert acoustic vibrations into an electrical signal, but usually they do so from direct contact with the strings (replacing the guitar's bridge) or with the guitar's body, rather than having a membrane like general-purpose microphones. Acoustic guitars may also use a piezoelectric pickup, which converts the vibrations of the instrument into an electronic signal. More rarely, a magnetic pickup may be mounted in the sound hole of an acoustic guitar; while magnetic pickups do not have the same acoustic tone that microphones and piezo pickups can produce, magnetic pickups are more resistant to acoustic feedback.

Standard amps
Standard amplifiers, such as the Fender "tweed"-style amps (e.g., the Fender Bassman) and Gibson amps, are often used by traditional rock, blues, and country musicians who wish to create a "vintage" 1950s-style sound. They are used by electric guitarists, pedal steel guitar players, and blues harmonica ("harp") players. Combo amplifiers such as the Fender Super Reverb have powerful, loud tube amplifiers, four 10" speakers, and they often have built-in reverb and "vibrato" effects units. Smaller guitar amps are also available, which have fewer speakers (some have only one speaker) and lighter, less powerful amplifier units. Smaller guitar amps are easier to transport to gigs and sound recording sessions. Smaller amps are widely used in small venue shows (nightclubs) and in recordings, because players can obtain the tone they want without having to have an excessively loud volume. One of the challenge with the large, powerful 4x10 Fender Bassman-type amps is that to get the tone a player wants, they have to turn up the amp to a loud volume.

These amps are designed to produce a variety of sounds ranging from a clean, warm sound (when used in country and soft rock) to a growling, natural overdrive, when the volume is set near its maximum, (when used for blues, rockabilly, psychobilly, and roots rock). These amplifiers usually have a sharp treble roll-off at 5 kHz to reduce the extreme high frequencies, and a bass roll-off at 60–100 Hz to reduce unwanted boominess. The nickname "tweed" refers to the lacquered beige-light brown fabric covering used on these amplifiers. 

The smallest "combo" amplifiers, which are mainly used for individual practice and warm-up purposes, may have only a single 8" or 10" speaker. Some harmonica players use these small combo amplifiers for concert performances, though, because it is easier to create natural overdrive with these lower-powered amplifiers. Larger combo amplifiers, with one 12 inch speaker or two or four 10 or 12 inch speakers are used for club performances and larger venues. For large concert venues such as stadiums, performers may also use an amplifier "head" with several separate speaker cabinets (which usually contain two or four 12" speakers).

Hard rock and heavy metal

Electric guitar amplifiers designed for heavy metal are used to add an aggressive "drive", intensity, and "edge" to the guitar sound with distortion effects, preamplification boost controls (sometimes with multiple stages of preamps), and tone filters. While many of the most expensive, high-end models use 1950s-style tube amplifiers (even in the 2000s), there are also many models that use transistor amplifiers, or a mixture of the two technologies (i.e., a tube preamplifier with a transistor power amplifier). Amplifiers of this type, such as Marshall amplifiers, are used in a range of the louder, heavier genres of rock, including hard rock, heavy metal, and hardcore punk. This type of amplifier is available in a range of formats, ranging from small, self contained combo amplifiers for rehearsal and warm-ups to heavy "heads" that are used with separate speaker cabinets—colloquially referred to as a "stack."

In the late 1960s and early 1970s, public address systems at rock concerts were used mainly for the vocals. As a result, to get a loud electric guitar sound, early heavy metal and rock-blues bands often used "stacks" of 4x12" Marshall speaker cabinets on the stage. In 1969, Jimi Hendrix used four stacks to create a powerful lead sound, and in the early 1970s by the band Blue Öyster Cult used an entire wall of Marshall Amplifiers to create a roaring wall of sound that projected massive volume and sonic power. In the 1980s, metal bands such as Slayer and Yngwie Malmsteen also used "walls" of over 20 Marshall cabinets. However, by the 1980s and 1990s, most of the sound at live concerts was produced by the sound reinforcement system rather than the onstage guitar amplifiers, so most of these cabinets were not connected to an amplifier. Instead, walls of speaker cabinets were used for aesthetic reasons. 

Amplifiers for harder, heavier genres often use valve amplifiers (known as "tube amplifiers" in North America) also. Valve amplifiers are perceived by musicians and fans to have a "warmer" tone than those of transistor amps, particularly when overdriven (turned up to the level that the amplifier starts to clip or shear off the wave forms). Instead of abruptly clipping off the signal at cut-off and saturation levels, the signal is rounded off more smoothly. Vacuum tubes also exhibit different harmonic effects than transistors. In contrast to the "tweed"-style amplifiers, which use speakers in an open-backed cabinet, companies such as Marshall tend to use 12" speakers in a closed-back cabinet. These amplifiers usually allow users to switch between "clean" and distorted tones (or a rhythm guitar-style "crunch" tone and a sustained "lead" tone) with a foot-operated switch.

Bass

Bass amplifiers are designed for bass guitars or more rarely, for upright bass. They differ from amplifiers for the electric guitar in several respects, with extended low-frequency response, and tone controls optimised for the needs of bass players.

Higher-cost bass amplifiers may include built-in bass effects units, such as audio compressor or limiter features, to avoid unwanted distorting at high volume levels and potential damage to speakers; equalizers; and bass overdrive. 

Bass amps may provide an XLR DI output for plugging the bass amp signal directly into a mixing board or PA system. Larger, more powerful bass amplifiers (300 or more watts) are often provided with internal or external metal heat sinks and/or fans to help keep the components cool. 

Speaker cabinets designed for bass usually use larger loudspeakers (or more loudspeakers, such as four ten-inch speakers) than the cabinets used for other instruments, so that they can move the larger amounts of air needed to reproduce low frequencies. Bass players have to use more powerful amplifiers than the electric guitarists, because deep bass frequencies take more power to amplify. While the largest speakers commonly used for regular electric guitar have twelve-inch cones, electric bass speaker cabinets often use 15" speakers. Bass players who play styles of music that require an extended low-range response, such as death metal, sometimes use speaker cabinets with 18" speakers or add a large subwoofer cabinet to their rig.

Speakers for bass instrument amplification tend to be heavier-duty than those for regular electric guitar, and the speaker cabinets are typically more rigidly constructed and heavily braced, to prevent unwanted buzzes and rattles. Bass cabinets often include bass reflex ports, vents or openings in the cabinet, which improve the bass response and low-end, especially at high volumes.

Keyboard
A keyboard amplifier, used for the stage piano, synthesizer, clonewheel organs and similar instruments, is distinct from other types of amplification systems due to the particular challenges associated with keyboards; namely, to provide solid low-frequency sound reproduction and crisp high-frequency sound reproduction. It is typically a combination amplifier that contains a two, three, or four-channel mixer, a pre-amplifier for each channel, equalization controls, a power amplifier, a speaker, and a horn, all in a single cabinet.

Notable exceptions include keyboard amplifiers for specific keyboard types. The vintage Leslie speaker cabinet and modern recreations, which are generally used for Hammond organs,  use a tube amplifier that is often turned up to add a warm, "growling" overdrive. Some electric pianos have built-in amplifiers and speakers, in addition to outputs for external amplification.

Acoustic amplifiers 
These amplifiers are intended for acoustic instruments such as violin ("fiddle"), mandolin, and acoustic guitar—especially for the way musicians play these instruments in quieter genres such as folk and bluegrass. They are similar to keyboard amplifiers, in that they have a relatively flat frequency response and avoid tonal coloration. 

To produce this relatively "clean" sound, these amplifiers often have very powerful amplifiers (up to 800 watts RMS), to provide additional "headroom" and prevent unwanted distortion. Since an 800 watt amplifier built with standard Class AB technology would be heavy, some acoustic amplifier manufacturers use lightweight Class D, "switching amplifiers."

Acoustic amplifier designs strive to produce a clean, transparent, "acoustic" sound that does not—except for reverb and other effects—alter the natural instrument sound, other than to make it louder. Amplifiers often come with a simple mixer to blend signals from a pickup and microphone. Since the early 2000s, it is increasingly common for acoustic amplifiers to provided digital effects, such as reverb and compression. Some also contain feedback-suppressing devices, such as notch filters or parametric equalizers.

Roles
Instrument amplifiers have a different purpose than 'Hi-Fi' (high fidelity) stereo amplifiers in radios and home stereo systems. Hi-fi home stereo amplifiers strive to accurately reproduce signals from pre-recorded music, with as little harmonic distortion as possible. In contrast, instrument amplifiers are add additional tonal coloration to the original signal or emphasize certain frequencies. For electric instruments such as electric guitar, the amplifier helps to create the instrument's tone by boosting the input signal gain and distorting the signal, and by emphasizing frequencies deemed desirable (e.g., low frequencies) and de-emphasizing frequencies deemed undesirable (e.g., very high frequencies).

Size and power rating
In the 1960s and 1970s, large, heavy, high output power amplifiers were preferred for instrument amplifiers, especially for large concerts, because public address systems were generally only used to amplify the vocals. Moreover, in the 1960s, PA systems typically did not use monitor speaker systems to amplify the music for the onstage musicians. Instead, the musicians were expected to have instrument amplifiers that were powerful enough to provide amplification for the stage and audience.  In late 1960s and early 1970s rock concerts, bands often used large stacks of speaker cabinets powered by heavy tube amplifiers such as the Super Valve Technology (SVT) amplifier, which was often used with eight 10" speakers.

However, over subsequent decades, PA systems substantially improved, and used different approaches, such as horn-loaded "bass bins" (in the 1980s) and subwoofers (1990s and 2000s) to amplify bass frequencies. As well, in the 1980s and 1990s, monitor systems substantially improved, which helped sound engineers provide onstage musicians with a better reproduction of their instruments' sound.  

As a result of improvements to PA and monitor systems, musicians in the 2000s no longer need huge, powerful amplifier systems. A small combo amplifier patched into the PA suffices. In the 2000s, virtually all sound reaching the audience in large venues comes from the PA system. Onstage instrument amplifiers are more likely to be at a low volume, because high volume levels onstage make it harder for the sound engineer to control the sound mix. 

As a result, in many large venues much of the onstage sound reaching the musicians now comes from in-ear monitors, not from the instrument amplifiers. While stacks of huge speaker cabinets and amplifiers are still used in concerts (especially in heavy metal), this is often mainly for aesthetics or to create a more authentic tone. The switch to smaller instrument amplifiers makes it easier for musicians to transport their equipment to performances. As well, it makes concert stage management easier at large clubs and festivals where several bands are performing in sequence, because the bands can be moved on and off the stage more quickly.

Amplifier technology 
Instrument amplifiers may be based on thermionic ("tube" or "valve") or solid state (transistor) technology.

Tube amplifiers

Vacuum tubes were the dominant active electronic components in amplifiers from the 1930s through the early 1970s, and tube amplifiers remain preferred by many musicians and producers. Some musicians feel that tube amplifiers produce a "warmer" or more "natural" sound than solid state units, and a more pleasing overdrive sound when overdriven. However, these subjective assessments of the attributes of tube amplifiers' sound qualities are the subject of ongoing debate. Tube amps are more fragile, require more maintenance, and are usually more expensive than solid state amps.

Tube amplifiers produce more heat than solid state amplifiers, but few manufacturers of these units include cooling fans in the chassis. While tube amplifiers do need to attain a proper operating temperature, if the temperature goes above this operating temperature, it may shorten the tubes' lifespan and lead to tonal inconsistencies.

Solid-state amplifiers

By the 1960s and 1970s, semiconductor transistor-based amplifiers began to become more popular because they are less expensive, more resistant to bumps during transportation, lighter-weight, and require less maintenance. In some cases, tube and solid-state technologies are used together in amplifiers. A common setup is the use of a tube preamplifier with a solid-state power amplifier. There are also an increasing range of products that use digital signal processing and digital modeling technology to simulate many different combinations of amp and cabinets. 

The output transistors of solid-state amplifiers can be passively cooled by using metal fins called heatsinks to radiate away the heat. For high-wattage amplifiers (over 800 watts), a fan is often used to move air across internal heatsinks.

Hybrid
The most common hybrid amp design is to use a tube preamp with a solid state power amplifier. This gives users the pleasing preamp and overdrive tone of a tube amp with the lowered cost, maintenance and weight of a solid state power amp.

See also
Amplifier
Electronic amplifier
Guitar amplifier
Guitar speaker
Guitar speaker cabinet
Isolation cabinet (guitar)
Valve sound
Bass instrument amplification
Effects unit
Distortion (guitar)
Power attenuator (guitar)
Sound reinforcement system

References

External links 
 Duncan's amp pages: information about valve (tube) guitar amplifiers
 List of books about guitar amplifiers and guitar amplifier tone
Tons of Tones, a website for guitar amplifier modelling on digital multi-effect units

Rock music instruments
Blues instruments
Sound reinforcement system
Consumer electronics
Loudspeakers